Storm drain systems are designed to drain excess rain and ground water from paved streets, parking lots, sidewalks, roofs, and the like. Excess rain and ground water typically enter a storm drain system via a drain-entry structure such as a catchbasin, manhole, or the like. The two most common types of catchbasins use either top inlets or side inlets (typically located adjacent to a curb). Manhole structures, which are typically larger than catchbasins, typically use a top inlet. In any case, the dimensions of the inlet opening are typically smaller than the dimensions of the bottom of the catchbasin, manhole, or other drain-entry structure directly below.
FIG. 1 illustrates a top-inlet-type drain entry structure 100 with a removable grating or grid 105 (shown removed to expose inlet opening 140 for maintenance). Top-inlet gratings (e.g. grating 105) are typically intended to prevent large objects and debris from entering the sewer system. However, their bars are typically fairly widely spaced so that the flow of water is not impeded. Consequently, many small pieces of debris 115, often including sand, silt, leaves, mud, rocks, small objects, and the like, are allowed to pass through top-inlet grating 105. As illustrated in FIG. 1, many of these small pieces of debris 115 are caught by sump 110 (also referred to as a “catch”), which lies directly below the grating. Side inlet catchbasins also allow small pieces of debris to collect in a sump.
Water 125 from the top of the sump 110 drains into the sewer proper (not shown) via outlet pipe 120. Most modern sumps extend at least a foot 135 below the bottom of outlet pipe 120. Some older sumps may extend as little as two inches below the bottom of outlet pipe 120.
Drain-entry structures generally require routine maintenance to remove accumulated debris 115 from the sump 110. Indeed, many jurisdictions mandate that landowners perform periodic storm drain maintenance. Many municipalities have large vacuum or “vactor” trucks that perform this task with a large vacuum hose 130 that sucks debris 115 from the sump 110 via inlet opening 140. Some private landowners may engage the services of a private vacuum truck to maintain drain-entry structures on their property, while other private landowners may have debris manually removed from drain-entry structures on their property such as with a shovel.
However, vacuum trucks are expensive to operate and/or engage, while manual drain-entry structure maintenance can be difficult and/or awkward, as many drain-entry structures are relatively deep and/or narrow, which makes it difficult to efficiently remove debris 115 with a manual shovel. Furthermore, many drain-entry structures (especially side-inlet and top-inlet catchbasins) have relatively small inlet openings (e.g. opening 140) that further hamper manual debris removal with a shovel.